It sucks but the new gears maps are going to cost some cash. How much, I can't tell you, but it looks like the maps will cost at first and then be free later on, much like the Halo 2 map model. Here's Epic's explanation:

"Quite frankly Xbox Live Marketplace isn't our store. It's Microsoft's store. Like any retailer they have the right to figure out what goes on the shelves of their store and what price they sell it at. They spend the money to operate the store and deliver the content. They've also spent billions of dollars to create and build Xbox and subsidize it's the price so you can afford it and we can make games for it. As our publisher, they also invested tens of millions of dollars marketing Gears of War, and have done an awesome job for us, so they have a right to a good return on that investment."